Spindle wood chips: coarse chips (6x4cm), little/no dust, no leaves or needles / obsolete log/spindle wood.
Pruning wood chips: fine chips, many small twigs (max 10 cm long) / pruning wood.
Softwood chips: coarse chips, max 10% needles, occasional twig (max. 20 cm long) / branch and top wood of conifers.
Hardwood chips: coarse chips, max 10% leaf, occasional twig (max. 20 cm long) / branch and top wood of deciduous trees.
Biofuel requires additional processing:
Coniferous chips (more than 10% needles): similar to softwood chips expect for too many needles / cause: too little woody mass was chipped along.
Deciduous chips (more than 10% leaf): similar to hardwood chips except for too much leaf / cause: too little woody mass was chipped along.
Wood chips for sieving: wood chips with long branches or wood splinters / cause: chipping with blunt knives / worn counter knife.
Wood chips with logging residues: wood chips contaminated with wood pieces that do not fit through chipper / cause: logging residues were mixed up with the good product.
